A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

A federal judge sentenced a former Arkansas judge Wednesday to five years in prison — a stiffer punishment than prosecutors recommended — after he admitted giving young male defendants lighter sentences in return for personal benefits that included sexual favours.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

In a 60 Minutes online exclusive, reporter Liz Hayes quizzed Australian Prime Minister Malcolm Turnbull on his relationship with the unpredictable Twitter aficionado and US president Donald Trump ahead of their meeting at the White House Friday.

Cup Day sublime, ridiculous, and tragic

It's always been a day of excitement but Melbourne Cup Day 2014 was a saga that ranged through the emotions.

German raider Protectionist stormed home to claim the Cup by four lengths in a flying finish to Australia's richest race.

But as the celebrations rolled on, the terrible news filtered through the crowd that Admire Rakti, Japan's Caulfield Cup winner and pre-race favourite had collapsed and died in his stall.

Hours later, another runner Araldo was put down after the stallion broke a bone in his leg when he was startled by a flag on his way back to scale, kicked out and struck a fence.

For the racing community, jubilation was shot through with sorrow.

Off the track, Cup Day was a mix of the glamorous and the garish, the sublime and the ridiculous.

Towering blonde US glamour girl Gigi Hadid led a line up of the impossibly beautiful and impeccably dressed celebrity types partying in the exclusive Birdcage marquees where some 10,000 bottles of French champagne will be sipped and guzzled during the eight-day Cup carnival.

Ty Wood, son of Rolling Stone Ronnie Wood, showed up but his dad's band failed to appear after rumours they would be surprise guests.

The Birdcage was also the scene of a "surprise" proposal when celebrity business type Geoffrey Edelsten dropped to one knee of his canary yellow suit to pop the question to his 25-year-old DJ girlfriend Gabi Grecko.

"I was speechless for maybe 15 minutes after because it was such a surprise," Grecko said after the cameras captured the moment.

She then lost the ring under a sofa, prompting her 71-year-old suitor to drop to his knees again on a recovery mission.

Outside the Birdcage, the punters as always put their own spin on dressing up for the Cup, as ninja turtles and superheroes mingled with suits and fascinators in a crowd of 100,794.

Clouds gave way to blue skies for the big race at 3pm and in 29C degree weather the masses were well-behaved as police removed just 10 people from the track and arrested two for drunkenness.

Protectionist's win is the sixth time an international horse has taken away the Cup.

On the track the best Australian finisher was third-placed Who Shot Thebarman after England's Red Cadeux ran second.

If further proof on the Cup's global appeal was needed, Twitter reported that the race was trending in Australia, New Zealand and the UK - countries represented by seven horses in the race.

Foreign "raiders" chasing the $6.2 million prize have worried racegoers but Protectionist will at least be staying on in Australia after it was bought, well before the race, by a local syndicate.

Meanwhile, the devastated connections of Admire Rakti await the results of a post-mortem.

Admire Rakti's jockey Zac Purton said he had sensed not all was right when the seven-year-old slowed dramatically in the final stage of the race before limping last across the line.

"I knew there was something wrong with him. I didn't know it was as bad as it was," he said.